(PDB-651) Fix spec failure on ruby 1.8.7

One of the new spec tests contained an expectation that used
a block argument destructuring syntax which has changed
between ruby 1.8.7 and ruby 1.9.3.  This commit fixes
the test to use a syntax that is compatible with both
ruby versions.
Merge pull request #980 from cprice404/bug/master/PDB-651-fix-spec-for-ruby-187

(PDB-651) Fix spec failure on ruby 1.8.7